Chain-mortising square hole cutting attachment for drill presses



July 14, 1953 A. FRANCESCA-m ErAL 2,645,255

CHAIN-MORTIZING SQUARE HOLE CUTTING ATTACHMENT FOR DRILL PRESSES Filed Aug. 20, 1948 3 Shoots-Sheet 1 iilllila Iililillll|Illillil alsislglllllliliial il!!! A. FRANcEscAT-n Erm. 256455255 CHAINMORTIZING SQUARE HOLE CUT'I'INGv y ,n

July .14, 1953 ATTACHMENT FOR DRILL. PRESSES Filed Aug. z.- 1948 s. srlletsf-snegt 2 A. CHAIN July 14, 1953 FRANCESCATTI ET AL -MORTIZING SQUARE :HOLE CUTTING ATTACHMENT FOR IDRILL. PRESSES Fiid' Ari@ .20, 'i549 IZOJL Francescai;

m 57 rf @tbm/nag *Patented `luly 14, 1953 y CHAIN -MORTISING SQUARE HOLE CUTTING ATTACHMENT FOR DRILL PRESSES Anton Francescatti and Richard Micek, Walsenburg, Colo.

Application August Z0, 1948, Serial No. 45,356Y

1 Claim.

This invention relatesto an improved tool for cutting square holes lor sockets, rectangular channels, mortises, grooves, or the like in either metal or wood. A

The general demand almost throughout the machining industry for a simple and eiicient tool, light in weight, which may be readily attached to present equipment to be driven thereby, or as easily detached, and used for cutting square holes, sockets, and the like is well recognized. Insofar as known, an individual heavy machine of one kind or another has alone been commercially offered for the purpose, but most if not quite all of such machines require several operations, such as milling' and broaching, and sometimes others, such as grinding or honing, to accomplish the object sought.

An object of the present invention, therefore, is to provide a simple and eicient tool which may be readily attached to or detached from a conventional drill-press and operated for cutting square holes, sockets, or the like, in metal or wood at a single operation.

A further object of the invention is to provide a tool embodying a cutting chain which, when the tool is attached to the drill-press, will be driven by the drill-press, under the usual controls of the drill-press, to accomplish a `desired cutting operation, and wherein the tool, as a whole, may be advanced or retracted by the drill-press in the customary manner, to cut into the work, or to lift therefrom.

And the invention seeks, as a still further object, to provide a tool which may be employed in connection with conventional drill-presses as now in general use. i

Otherand incidental objects of the invention will appear during the course of the following A description, and in the drawings:

Figure 1 is a perspective View showing our improved cutting tool applied to a conventional drill-press. i

Figure 2 is a fragmentary side elevation `of the tool.

Figure 3 is a vertical section taken laterally from side to side through the tool.

Figure 4 is a vertical sectional view taken from front to rear through thedevice.

Figure 5 is an enlarged detail side elevation of a portion of the cutting chain.

Figure 6 is a section on the line 6-5 of Fig-` a typical com-l Figure 9 is an enlarged fragmentary rear elevation of the cutting chain.

Figure 10 is a fragmentary enlarged front elevation of the cutting chain.

Figure 11 is a horizontal section particularly showing the guide bracket for the cutting tool.

Figure 12 is a fragmentary perspective View showing the use of a modified form of guide bracket.

Figure 13 is a view partly in section and partly in elevation and showing the modified form of guide bracket.

Figure 14 is a detail perspective View of the headpiece of the modied form of guide bracket.

Referring now more particularly to the drawings, We have shown a conventional drill-press embodying a base I0 from which rises a post II.

-The motor of the drill-press is indicated at I2,

and the usual chuck thereof at I3, said chuck being rotatable, as will be well understood, by the motor. The customary handle for raising or lowering the chuck, as will also be Well understood, is indicated at I4. Adjustable vertically on the post II as well as rotatably adjustable thereon is the usual table I5. All of the foregoing structure and the operation thereof'is Well known in the art rand requires no detailed description. In the present instance, we have shown a block of work I6 on the table I5.

In carrying the invention into eiect, we e ploy an oblong frame Il of more or less: skeleton construction. This frame includes a box-like head I8 from which extends a stock I9 rectangular in cross section and having a, longitudinal slot 20 therein. Closing the head I8 at its lower side is a web 2I, and formed on the stock at its lower end is a yoke 22. Rising from the upper side of the head I8 is a bearing 24, and upstanding from said bearing is a stub shaft 25.

Journaled through the head I8 of the frame I'I is a drive shaft 26 on one end of which is mounted an idler gear 21, and pinned or otherwise fixed to the opposite end of said shaft is a gear 28. Resting upon the bearing 24 is a cupped drive gear 29 meshing at its lower periphery with the gears 2l and 28, and rising from the gear 29 is an axial stem 30 rotatably fitting the stub shaft 25 of the frame. Engaged with the upper end of said stub shaft is a cap screw 3| detachably securing the drive gear in position.

As will now be apparent from the foregoing, if the frame II is held against rotation, turning of the drive gear` 29 will serve to rotate the shaft 26 through the medium of the gear 28. The idler gear 2l is provided to equalize the load as between the ends of said shaft.

Fixed to the shaft 26 isa drive sprocket A32, and journaled in the yoke 22 is a coacting sprocket 33 mounted by a pin 34. Engaged through the side plates of the yoke to enter the ends of said pin are cap screws 35 detachably mounting the pin and sprocket. As will be observed, the sprockets 32 and 33 are provided with medial annular grooves 36.

Trained about the sprockets 32 and 33 is a cutting chain, indicated as a whole at 3l. A typical individual cutting link 38 of the chain is shown in Figure 7. As will be noted, the link is formed at its rear edge with a notch 39 which denes lobes 40 at the ends of the link, and formed on the forward edge of the link, more or less near the heel portion thereof, are cutting teeth 4I.

The cutting chain 3l further embodies a combined cutting and guide link 42, shown in detail in Figure 8 of the drawings. `l'he link i2 is similar to the link 38 in that the link 122 is provided at its forward edge more or less near the heel portion thereof With cutting teeth 43. However, the link 42, instead of being provided at its rear edge with a notch, as the link 33, is formed with a straight rear edge. In other words, the link i12 is, over all, symmetrically oblong.

As seen in Figures 5 and 6 of the drawings, the links 38 and 42 are digitated to form the chain A3l and are connected at their vmeeting ends by transverse pivot pins dii somewhat oval in cross section so that the chain may iiex freely around the sprockets 32 and 33, one of which pins, of no `particular interest, is endwise removable so that the chain may be readily assembled about the sprockets or removed therefrom.

Looking at the rear of the chain 3l, as shown in Figure 9, itv will be seen that the transverse aligned links 38 provide, through the medium of the notches 39, transverse grooves 45 to accommodate the teeth of the sprockets 32 and 33, and transverse rows of teeth 56, provided by the lobes 40, to coact with the teeth of the` sprockets, so that as the sprocket 32 is rotated, the cutting chain-will be driven to turn about both sprockets.

It is also envisioned to prevent sidewise slippage of the cutting chain 3l, as this feature is important in order that the chain shall cut true. To this end, the combined cutting and guide links #i2 are provided. As seen in Figure 9, these links of the chain are arrangedinv a series medially of the chain so that thestraight rear edges thereof will be received in the grooves 3G of the sprockets 32 and 33, as the chain travels. Consequently, these links will coact Ywith the sprockets to guide the chain in a straight path and prevent lateral .displacement of the Vchain as it bites into the work.

Looking now at the front face of the cutting chain 31, as enlarged in Figure 10, it will be noted that, referring back to Figure '7, the uppermost of the aligned teeth 4| of a given transverse row of links form one transverse row of teeth, and the lowermost of said teeth form another transverse row of teeth, while below the lowermost row of teeth is provided a clearance space 41 next between repeating sequence of rows of teeth. It has been found in practice that the clearance space 41 is necessary as a channel to accommodate shavings, or as perhaps may be better said, grains, or small bits of cuttings. Otherwise, the chain tends to choke. For such reason, the teeth 4| or 43 are located near the lieti @i @ach link respectively.

The stem 30 of the drive gear 23 is of" a size\ to be removably accommodated in the usual chuck of a conventional drill-press, and, in Figure 1 of the drawings, we have shown the device so engaged with the chuck I3 of the. drill-press typified. As will be appreciated, in view of the foregoing description, the chuck I3, when driven, will turn the stem 30, and so rotate the gear 29. As previously noted, it is necessary to lock the frame I'| of the tool against rotation in order to effect rotation of the cutting vchain 3l. To this end, we provide a bracket, indicated as a whole at 38. This bracket includes, as best seen in Figure 11, a collar 49 detachably'engaged about `the post of the drill-press for adjustment `vertically of the post, and extending from one arcuate portion of the collar is an arm 53. Adjustable longitudinally of said arm are yoke plates 5| which straddle the frame il, and eX- tending through said plates and through the slot 23 ofthe stock of the frame is a removable locking pin 52. Thus, the bracket 43 will not only hold the frame |'I against turning movement but also, the pin 52 will guide the frame in its vertical movement as the tool is raised or lowered.

Assuming now that the tool is attached. to a drill-presa'as shown in Figure 1, it will be seen that the motor of the drill-press may be operated under the usual controls of the drill-press to drive the cutting chain 3l, while the handle Il! of the drill-press may be manipulated to either raise the tool or lower the tool to engage the work i6 for cutting a square hole therein, or if desired, a square socket therein.

In Figures 12, 13, and 14 of the drawings, we have shown a modied form of bracket adapting `the tool to cut channels or mortises in long pieces of work.-

As seen in Figure 12, the table I5 of the drillpress is swung aside, and attached to the post |i is a bracket 53 Vembodying an adjustable collar 54 from which extends an arm 55. Adjustable upon said arm is a head-piece 53, seen in detail in Figure 14 of the drawings. This head-piece includes a stem 51 which extends through the slot 20 of the stock i9 of the frame i? of the tool, and is formed at the base of the stem with a collar 58, while at the outer end of the Vstem is provided a head 59. By aligning the head with the slot 20, the head may be freely inserted through said slot, after which the head is turned to horizontal position so that the frame will thus be confined between the head and collar and thus limited against lateral displacement. f

It is now to be noted that in Figure 1 ofthe drawings, the cutting chain 3i is presented in what may be described as a forward and rear position with respect to the post I| of the drillpress, whereas, in Figure 12, the cutting chain is presented laterally. A door, or other work, as conventionally shown at 60, may thus be disposed with one longitudinal edge up at one side of the table I5 for engagement by the tool, and moved longitudinally as the cutting operation progresses so that the chain 3l may cut a longitudinal slot as long as desired at a chosen point along the upper edge of the door.

Having thus described our invention, we claim:

A cutting tool of the character described including a frame having a stock provided with a head and formed with a longitudinal slot therein, a stub shaft rising from said head, a drive shaft journaled through said head and having a gear fixed thereon, a sprocket carried by the drive shaft, a second sprocket journaled upon the lower end of said stock, a cutting chain trained about said sprockets and having its reaches between the sprockets extending parallel to the side Walls of said slot, a drive gear meshing with the former gear and having a tubular stem journaled upon said stub shaft, said drive gear being freely removable at the upper end of said stub shaft, fastening means engaging the upper end of the stub shaft and coacting with said stem to removably secure the drive gear in position, said stem with its fastening means being receivable in the vertically movable chuck of a drill-press for actuation of the stem thereby to rotate the drive gear and turn said chain about the sprockets, and means xed to the drill-press for locking the frame against rotation and including an element extending through said slot of the stock and adapted to guide the frame vertically as said chuck is raised or lowered.

ANTON FRANCESCATTI. RICHARD MICEK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 155,111 Schoeld Sept, 15, 1874 449,703 Riedel Apr. 7, 1891 477,528 Gillespie June 21, 1892 1,170,120 Slonaker Feb. 1, 1916 1,690,697 Palmu Nov. 6, 1928 2,197,210 Forrest Apr., 16, 1940 2,351,112

Day June 13, 1944 

